fix: cache dynamic imports

[OrKoN]

Closes #8650

[jrandolf]

Node should do this themselves....facepalm

[Kikobeats]

I really will appreciate some explanation how what's happening here; I'm trying to understand how the perf degradation was caused and how this PR resolve the thing, but is very unclear to me; I don't understand why these helpers are even necessary 😅

[prarabdhb]

@Kikobeats From what I understood, in the previous implementation, fs or debug was imported every time the import statement was encountered. To ensure this doesn't happen, this PR stores fs in a variable fs so that it is not imported every time, improving the performance as importing can be an expensive task.

[Kikobeats]

I still feel very lost since modules (ESM/CJS) are singleton by nature, so it doesn't matter how much times you import them, it will be cached in the first call

[jrandolf]

I still feel very lost since modules (ESM/CJS) are singleton by nature, so it doesn't matter how much times you import them, it will be cached in the first call

This is a reasonable assumption, but sadly this is probably not the case based on the stats.